A grinding wheel disclosed in Japanese Patent Laid-open Publication No. 2000-354969 ([0007], [0026], FIG. 1), includes an abrasive grain layer in which inclined grooves are formed on a grinding surface formed on a periphery of the abrasive grain layer. More specifically, the abrasive grain layer contains superabrasive grains such as diamond or cubic boron nitride, and is adhered to a periphery surface of a disc-type core that is rotated about its axis. The inclined grooves have a predetermined width and depth, and are inclined at an angle of approximately 25 to 45 degrees to the axis of the core. Compared with the conventional grinding wheel having no grooves, the grinding wheel having grooves increases the grinding amount approximately 1.5 times because grinding fluid can be effectively introduced into a grinding point along the inclined grooves.
Further, grinding fluid introduced into a grinding point generates a dynamic pressure between a workpiece and a grinding wheel. Such pressure causes the workpiece to displace relative to the grinding wheel, thereby decreasing machining accuracy and efficiency. It is considered to release the dynamic pressure by forming the grooves on the grinding surface of the grinding wheel. In addition, it is also considered to form a plurality of holes on the grinding surface of the grinding wheel, instead of such grooves, in order to release the dynamic pressure.